I know many kids that would care even less about their grades if it wasn't for sports. Sports does bring out the worst in people (mostly parents) but the positives defiantly out way the negatives. Having a strong sports program probably means the band and choir are participating, many kids go just to hang out with friends, brings a closeness to the community, etc etc. My high school growing up has a lot of tradition up and down sports, cheerleading, band etc. The general feel for the school is upbeat and fun.
I have coached at other high schools where the sports programs stink for the most part and the general vibe of the school was a loser mentality. When I first got hired at this school as the varsity head basketball coach the school was on a 54 game losing streak with the average margin of defeat 38pts per game. My first week I asked the wresting coach what made his program successful (only one in the school). He said I tell my kids remove yourself from the loser mentality of the school and just focus on us (winners). He had a lot of success with his program on and off the mat. I tried the same thing but had nothing but resistant from admin (hence the loser culture). Eventually, I was able to over come the culture and turned the worst program in the state to conference and district champions (first time) and go to state (first). I left after that year due to parents and being sabotage by assistants wanting the glory. Admin didn't back me up and wouldn't do what needed to be done, so I left for greener pastures. The time I was there you could see the attitudes and culture shift from the whole student body. They went from high school (ugh) to high school (fun) lets make something out of this. Not just the players but much of the student body. The school just needed an attitude adjustment and sometimes it takes sports to do it. I just had a parent the other day comment to me how awesome that year was and how much different the school was.
I'm not saying sports doesn't bring negatives with it, but over all, a strong sports programs make the high school experience for the school as a whole, much my enjoyable. I have seen and experienced it myself. Just my observation and opinion from one whose involved with this on almost a daily basis.